Method and apparatus for operating on shoes



Jan. 11, 1938. C. K. MacDONALD 2,105,427

METHOD AND APPARATUS FOR OPERATING ON SHOES Filed Nov. 2, 1956 2 Sheets-Sheet l Fig.1

Jan. 11, 1938. c. K. M cDONALD METHOD AND APPARATUS FOR OPERATING ON SHOES Filed Nov. 2, 1936 2 Sheets- Sheet 2 Patented Jan. 11, 1938 METHOD AND APPARATUS FOR OPERATING ON SHOES Application November 2, 1936, Serial No. 108,740

15 Claims.

This invention relates to methods and apparatus for operating on shoes and is illustrated herein with reference to improved methods and apparatus for removing soles from shoes.

Objects of the invention are to provide an improved method and an improved apparatus for removing from shoe bottoms outsoles which have been attached thereto by a strong bonding cement, and to provide an improved hand device for accomplishing the same purpose.

There are a number of cements in use today for attaching soles to shoe bottoms which have an exceptionally strong bonding power and a tenacity in holding the sole to the shoe bottom which effectively resists and sometimes prevents removal of the sole from the shoe, for example, in repair work without damaging the shoe upper. One example of this cement is a synthetic rubberlike composition made by polymerizing chloroprene and known commercially as Du Prene. The use of such a cement for attaching soles to shoes is disclosed in United States Letters Patent No. 2,061,296, granted November 17, 1936, upon an application filed in the name of Walter H. Wedger. A characteristic of a cement of this type is that,

instead of taking on a hard glassy appearance after it has become aged or cured, it retains some of its original elasticity so that when it is attempted to peel the sole from the shoe bottom by the means usually employed for that purpose, the cement will not let go. If extreme force is applied to tear the sole away from the shoe bottom this cement will cling to both the sole and the shoe bottom and will stretch and thereby effectively 3 resist the action of ordinary tools in freeing the sole from the shoe.

In accordance with one feature of the present invention means is provided for penetrating the film of cement between a sole and a shoe bottom as the sole is pulled away from. the shoe, said means having projections thereon to facilitate its penetrating action. In accordance with another ieature of the invention, means is provided for heating the penetrating means to sever the stringy fibers of the cement and thereby to assist in breaking the bond between the sole and shoe bottom. As herein illustrated, the penetrating means comprises a rigid blade having projections or teeth thereon especially adapted to penetrate the film of cement without cutting into the parts operated upon. The means for heating the blade to break the cement bond as the blade comes into contact therewith is arranged to maintain said blade at a fairly constant temperatue at least high enough to break the cement bond and render it non-adhesive. The projections on the rigid blade and the heat for severing the cement bond permit the blade to pass fairly rapidly between the attached portions of the sole and shoe, thereby insuring that the heat of the blade will not scorch the shoe upper. The projections on the blade also prevent it from slipping out from between the sole and the shoe bottom during the sole removing operation. Furthermore, the substantially instantaneous breaking of the cement bond by the application of sufiicient heat obviates the necessity of applying excessive force in removing the sole from the shoe bottom, thereby further preventing the damaging of the shoe upper.

In another aspect the invention provides an improved method for removing from shoe bottoms soles which have been attached thereto by a strong bonding cement which comprises pulling a sole away from its shoe bottom to stretch the cement layer located therebetween, and applying pressure and heat to the stretched layer of cement with the aid of a heated blade to break the adhesive bond between the sole and the shoe bottom.

With the above and other objects and features in view the invention will now be described in connection with the accompanying drawings and thereafter pointed out in the claims.

In the drawings,

Fig. 1 is a side elevation of an apparatus embodying the present invention operating on a shoe;

Fig. 2 is a front elevation of the operating instrmnentalities of the apparatus;

Fig. 3 is a front elevation of a hand device or tool forming a modification of the invention, the device being shown operating on a shoe;

Fig. 4 is a side elevation partly in section of the hand device;

Fig. 5 is a fragmentary View, on an enlarged scale, of the work engaging portion of the hand device; and

Fig. 6 is a perspective view of the lower portion of the hand device operating on a shoe.

The apparatus illustrated herein for removing cement attached soles from shoes comprises an upstanding base or frame iii (Fig. 1) the upper end of which is bifurcated and provided with flanges i2, M which support a carrier member N5 of heat conducting material such as brass or copper secured to the flanges by screws l8 and spaced therefrom by bushings 20 of some insulating material such, for example, as asbestos surrounding the screws.

At its upper portion the carrier member l6 has mounted therein a heating unit 22 connected in any usual manner to an electric current by a switch 2Q whereby the unit may be energized to heat the carrier member it. While heating units of various sizes may be utilized, depending largely upon the degree of heat found to be most satisfactory for the particular type of work to be operated upon, a watt-unit capable of generating a heat of between 300 to 400 F. has been found to be very satisfactory in removing soles which have been attached to shoes by a strong bonding cement of the type referred to. If, for economy or other reasons, a smaller heating unit is desired, it should at least be of such wattage that it will not only supply the heat required for the work to be performed, but will also maintain this heat fairly constant notwithstanding losses by radiation or by conduction due to contact of the heated parts with heat conducting materials such, for example, as the steel shank piece in a shoe. In other words, the unit should be of such a size that it will generate enough heat to balance or offset the heat lost through radiation or otherwise and will thus maintain a substantially constant temperature which is sufficiently high to perform the work.

The lower portion of the carrier member 16 is slotted vertically at 26 (Fig. 1) and in this slot is mounted a rigid work engaging member or blade 28. As shown in Figs. 1 and 2, the upper portion of the member 28 is relatively thick, for example, of an inch in cross section and the work engaging portion thereof is preferably about of an inch thick with its lower periphery substantially semicircular in shape. The blade is composed of metal such, for example, as iron or steel so that it can be heated to a temperature of from 300 to 400 F. It is secured in the slot 25 by a pair of screws 3! so that it will not move when operating on a shoe. The semicircular periphery of the blade 28 is provided with projections or teeth 32 (Fig. 2) which are especially constructed to penetrate the opening between a shoe bottom and its outsole without cutting into the shoe upper. trated more clearly in Fig. 5 in connection with the hand device to be later described and are designated in that figure and in Fig. 4: by the reference numeral 32. As shown in Fig. 5, the teeth 32 may be from to of an inch long on their work engaging edges and are spaced from each other about the same distance. The teeth are beveled toward their work engaging edges to facilitate their introduction between a sole and shoe bottom but the teeth are not brought to a cutting edge and accordingly are fairly blunt. As shown in Fig. 4, the teeth 32 are not ofiset, as are the teeth of a saw but, on the contrary, have their work engaging edges directly in line with each other.

In using the apparatus the switch 24 is turned on to cause the heating unit 22 to heat the carrier member i 5 and blade 28 to the required temperature which will thereafter remain substantially constant throughout the sole removing operation. The shoe is presented to the apparatus, as shown in Fig. 1, and in accordance with the method herein disclosed the blade 28 is inserted between the opening or crease at the toe end of the shoe. The shoe is then rocked from side to side to permit the work engaging edge of the blade to penetrate into the layer or film of cement between the sole and the shoe upper a sumcient distance to allow the operator to grasp the end of the sole. He then pulls the free end of the sole away from the shoe bottom and rolls the These projections 32 are illus-' shoe from side to side as he moves it upwardly against the blade so that the latter passes alternatively down one side and then the other of the forepart of the shoe between the opposite lasting margins of the upper and the portion of the sole attached thereto. The projections or teeth 32 on the blade penetrate the film of cement without cutting into the shoe upper, and the heat of the blade breaks or severs the stretched strings of cement as the sole is pulled away from the shoe bottom by the operator. The heat is suilicient to destroy the adhesive bond of the cement upon contact of the blade therewith, thereby permitting the shoe and sole to be moved along the blade with suiii'cient speed to insure that the heat will not scorch the shoe upper. After loosening the forepart of the sole the operator may, if desirable, remove the filler material at the forepart of the shoe bottom and then proceed to separate the shank portion of the sole from the shoe by a similar operation. In breaking the cement bond between the shank portion of the sole and the shoe bottom the operator preferably manipulates the blade so that the steel shank piece in the shoe will not interfere with the sole removing operation. In this way a sole which has been attached to a shoe by a strong bonding cement such as Du Prene may be readily removed from the bottom of a shoe without tearing, cutting, scorching or otherwise damaging the overlasted portion of the shoe upper to which a new sole is to be attached.

The modification of the invention embodied in the hand device referred to is illustrated in Figs. 3 to 6 inclusive. This device embodies the features of the invention described above but may be more convenient to use under some conditions since it can be carried about from place to place and connected to an electric circuit wherever convenient. The hand device comprises a work engaging member or blade 34 illustrated herein as circular in shape and about two and one-half inches in diameter and {a of an inch thick, the blade having formed on its periphery the work engaging projections or teeth 32' described above. The blade 34 is rigidly secured in a heat conducting bearing 35 preferably formed of brass and having its lower portion slotted to form legs 38 which bear against the blade. The blade 35 is formed of iron or steel so that it can be heated to a relatively high temperature and a hole about an inch in diameter is formed in its central portion for receiving a brass plug or core M for transmitting heat to the blade. The blade a is secured between the legs 38 of the bearing by a rivet 52 which passes through the core 50. The forward leg 33 of the bearing 36, as viewed in Fig. 3, has mounted thereon, by a screw #4, a spring plate 56 preferably of brass and the opposite side portions of which are bent inwardly and bear against the blade 3%, thereby assisting in transmitting more heat to the operating portion thereof. The screw 4 bears against the upper portion of the blade and thus holds it rigidly in the bearing 35.

The upper portion of the bearing 36 is cylindrical and is threaded internally (Fig. 4) to receive the end of a heating unit @8 similar to that described above and the other end of which is threaded into a metal collar or bushing 5% preferably of brass or other heat conducting material and having an upwardly extending hollow stem 52 through which pass wires 54 to conduct an electric current for heating the unit. The bushing 50 is secured in a frame which surrounds the heating unit and acts as a guard so that the device may be handled and operated conveniently while the unit is hot. This frame comprises an insulating member 56 to which the bushing 55 is clamped by a nut 58 threaded on the hollow stem 52 and bearing against insulating washers 6B. The bushing is also insulated from the member 56 by similar washers 62 bearing against the lower side of that member.

Extending through holes in opposite end portions of the member 56 are a pair of metal rods Ki i having their lower portions spaced from the heating unit 48 and extending downwardly into a casting ".55 preferably of aluminum and provided with a tapered central opening in which the bearing 36 is supported by contacting with only the lower portion of the casting. The rods 64 are secured in the casting 66 by nuts 68, IE! threaded on the rods and bearing against insulating washers E2. The upper portions of the rods 64 are surrounded by a pair of tubes 74 whereby heat is conducted from the unit 48 to the work engaging portion of the blade. Moreover, the frame formed by the casting 66, the rods t l, and the tubes '14 which, it will be noted, form a handle for operating the device manually, insulate the frame from the heating unit and the blade 34 so that very little heat is lost by passing into the frame.

In operating on a shoe the blade 34 is preferably introduced between the sole and shoe at the toe end thereof and is worked back and forth laterally of the shoe bottom until the toe end of the sole has been loosened sufficiently to permit the sole to be grasped by the operator. The operator can then hold the shoe between his knees or, if more convenient, on a jack on a bench, and roll the hand tool so that it enters alternatively between the overlasted margins of the upper and the attached portions of the sole at opposite sides of the shoe as the sole is pulled away from the shoe bottom. As stated above, the action is such that, upon engagement of the heated blade 3G with the film of cement, which is stretched into minute strings or threads by the force exerted by the operator in pulling a blade can be advanced continuously and fairly rapidly between the shoe bottom and the outsole without danger of cutting or otherwise damaging the overlasted portions of the shoe upper. After separating the forepart of the sole from the shoe bottom, the operator may remove the filler piece, if necessary, and, as shown in Fig. 6, may separate the shank portion of the shoe by a continuous rocking motion of the tool, this motion being altered somewhat at the shank to avoid interfering with the steel shank piece located at this portion of the shoe bottom.

The advantages of removing soles which have been attached to shoes by a strong bonding cement of the type referred to by the method disclosed herein and with the aid of the apparatus or hand device of the present invention will be apparent since the danger of permanently damaging the shoe upper by cutting, tearing or scorching is eliminated and these devices permit the sole to be quickly removed without the operator exerting the force which has heretofore been necessary to accomplish this result. Moreover, as pointed out above, the work engaging members or blades 28 and 34 of the apparatus and hand device respectively are maintained at a substantially constant high temperature and accordingly either may be used continuously in removing soles from shoes, thereby saving the time that would ordinarily be required to keep these members at the proper temperature when operating successively on a large number of shoes.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. An apparatus for operating upon shoes having, in combination, a non-movable member adapted to be inserted between a shoe and a sole cement attached thereto for separating the sole from the shoe, said member having relatively blunt means thereon for penerating the cement which secures the sole to the shoe bottom, and means for heating said member to cause said blunt means to break the cement bond during penetrating movement of said member in one direction only.

2. An apparatus for operating upon shoes having, in combination, a substantially flat rigid member adapted to be inserted between a shoe bottom and a cement attached sole to separate the sole from the shoe bottom, the operating edge of said member being semi-circular in shape and having projections thereon arranged to penetrate the cement by which the sole is attached to the shoe without cutting into the shoe upper, and means for heating said member to cause said projections to break the cement bond during the penetrating action thereof.

3. An apparatus for operating upon shoes having, in combination, a non-reciprocating member adapted to be inserted edgewise between a soleand a shoe bottom to separate the sole from the shoe, the operating edge of said member being serrated for penetrating the means securing the sole to the shoe bottom, means for heating said member to a temperature that will break said securing means without damaging the parts operated upon, and insulating means for maintaining said temperature substantially constant.

a. An apparatus for operating upon shoes having, in combination, a non-rotatable circular member adapted to be inserted between a cement-attached sole and its shoe to separate the sole from the shoe bottom, the operating edge of said member being shaped to facilitate its introduction between the sole and the shoe bottom but being relatively blunt to prevent injury to the parts operated upon, and means for maintaining said member at a temperature that will destroy the cement bond as the member passes between the sole and the shoe bottom without damaging the shoe upper.

5. An apparatus for operating upon shoes having, in combination, a flat blade for entering the crease between a shoe bottom and a cementattached outsole to separate the outsole from the shoe, the operating portion of said blade being substantially semi-circular in shape and having blunt teeth on its periphery for penetrating the cement film between the outsole and the shoe without cutting the shoe upper, and means for heating said blade to a temperature that will destroy the cement bond as the teeth penetrate the latter, said means being constructed and arranged to maintain the blade at a substantially uniform temperature.

6. An apparatus for operating upon shoes having, in combination, a rigid frame, a member on the frame adapted to be inserted. between a shoe bottom and a sole attached to the shoe by a strong bonding cement, the operating edge of said member being convexly curved to facilitate its introduction between the sole and the shoe bottom and having blunt projections thereon adapted to penetrate into the cement without scarring the shoe upper, means for holding said member fixed relatively to the frame, and means for heating said member to sear the cement as the member passes between the sole and the shoe bottom and thereby to break the bond which secures the sole to the shoe.

7. In an apparatus for operating upon shoes, the combination of a frame, a toothed member fixed on said frame for entering the crease between shoe and a cement-attached outsole and separating the shoe parts from each other, means on the frame contacting with said toothed member for transmitting heat thereto, and means for preventing the heat in said member from spreading to adjacent portions of the frame.

8. In an apparatus for operating upon shoes, the combination of a supporting frame a member fixed on said frame for entering the crease between a shoe and a cement-attached sole and separating the sole from the shoe bottom, the operating edge of said member having relatively blunt projections thereon for penetrating the cement between the sole and the shoe bottom, means for heating said member to break the cement bond as the teeth penetrate the cement, said means being constructed and arranged to maintain the fixed member at a predetermined temperature to prevent scorching the shoe parts, and means for insulating the fixed member from the frame to prevent the heat in said member from passing into the frame.

9. In a device for operating upon shoes, the combination of a frame, a member on the frame adapted to be inserted between a shoe bottom and a sole attached to the shoe by cement, the operating edge of said member being convexly curved to facilitate its introduction between the sole and the shoe bottom, means for holding said member stationary relatively to the frame, and blunt projections on said operating edge constructed and arranged to penetrate the cement which secures the sole to the shoe without damaging the shoe bottom.

1%. In a device for operating upon shoes, the combination of a supporting frame, a substantially circular blade fastened in the frame and to enter the crease between a shoe bottom and an outsole attached thereto by a strong bonding cement and to separate the outsole from the shoe bottom, the operating edge of said blade having beveled teeth thereon arranged to penetrate the cement film between the shoe bottom and the outsole without scarring the shoe upper, a core in said blade for transmitting heat thereto, a heat-conducting bearing connected to said core and passing through said frame, a heatconducting member fastened to said bearing and contacting with a portion of the blade remote from its operating edge, a heating unit secured in said bearing, said frame surrounding said heating unit, and means on said frame for insulating it from the heating unit and the blade, thereby permitting the device to be handled by an operator to separate the outsole from the shoe bottom while the blade is hot.

11. An apparatus for operating upon shoes having, in combination, a rigid member for entering the crease between a shoe bottom and a cement-attached sole and separating the sole from the shoe, said member having a semi-circular operating portion wide enough to extend across the cemented margins of the sole and shoe and the periphery of said portion being serrated but relatively blunt to penetrate the cement layer between the sole and shoe bottom without scarring the shoe upper, and means for maintaining said member at a temperature that will break the adhesive bond between the sole and shoe and thereby permit the ready removal of the sole from the shoe without cutting said shoe parts.

12. That improvement in methods of removing soles from shoes which comprises applying force to pull a sole away from its shoe bottom, thereby exposing the means securing the sole to the shoe, andbreaking said securing means by the application of pressure and heat alone without any cutting or shearing action.

13. That improvement in methods of removingcement attached soles from shoes which comprises positively pulling a sole away from a shoe bottom with a force sufficient to expose the film of cement therebetween, and applying heat pressure in one direction only to said film, thereby breaking the cement bond.

14. That improvement in methods of removing from shoe bottoms soles which have been attached thereto by a strong bonding cement which may be rendered non-adhesive by heat which comprises pulling a sole away from a shoe bottom sufficiently to stretch the cement layer between the sole and shoe,and forcing a single non-rethereby preventing cutting of the shoe parts operated upon.

CLIFFORD K. MACDONALD. 

